Behavior of Underground Piping Joints Due to Static and Dynamic Loading

Keywords: Underground pipe joints.  Unrestrained pipe joints.  Restrained pipe joints.  Testing.  Pipelines.  Dynamic behavior.  Seismic behavior.  Systems analysis.  Risk assessment.

Abstract: This MCEER report describes the procedures and results of an empirical data research program designed to determine the static and dynamic behavior of some typical restrained and unrestrained underground pipe joints.  Because pipelines have suffered damage and failure during past earthquakes, and because it is well-documented that a majority of these failures occurred at unrestrained pipe joints, both unrestrained and restrained pipe joints have been examined to help mitigate potential damage and failure.  Five different material types with eight different joint types and several different pipe diameters were used in this testing program.  The test results are provided as load-displacement plots, moment-rotation plots, and tables listing the axial and rotational stiffness, force capacities, and bending moment capacities.  A comparison is made between static and dynamic results to determine if static testing is sufficient to characterize the dynamic behavior of pipe joints.  This report also suggests methods to use the test results for a finite element pipeline system analysis and for risk assessment evaluation.